诱虫植物香根草控制水稻二化螟的最佳田间布局

Optimal planting pattern of trap plant vetiver grass,Vetiveria zizanioides,for controlling rice striped stemborer,Chilo suppressalis

为明确诱虫植物香根草控制水稻二化螟的最佳田间布局,进行了不同种植年限和丛间距的香根草条带对控制水稻二化螟作用距离和效果的研究。结果表明,在为害程度远低于防治指标的二化螟轻发生区,田埂上种植了一年和二年香根草的稻田螟虫枯心率均显著低于没有种植香根草的对照田,其中种植了二年香根草的稻田比种植了一年香根草的稻田对螟虫的控制效果更好,丛间距为5、3和1m的二年生香根草条带对早稻的平均保苗效果分别为63.6%、47.5%和69.7%,有效作用距离达到20m以上。在二化螟常年发生较重(85.45头/百丛)的地区,大田验证试验结果表明,香根草丛间距4m、行间距50m时,稻田二化螟越冬代幼虫的虫口减退率达到84.2%。通过研究明确了稻田四周田埂或路边种植香根草控制水稻二化螟的最佳田间布局为:丛间距3~5m、行间距50~60m。

In order to clarify the optimal planting pattern of the trap plant vetiver grass,Vetiveria zizanioides for controlling rice striped stemborer(SSB),Chilo suppressalis in rice fields,the control range and effect of vetiver grass stripe with different cultivation age and cluster spacing to SSB were investigated in this study.The results showed that,in the areas where the extent of the damage were far below the control index,rice dead heart rates in the paddy field with1-year and 2-year vetiver grass trap stripe were significantly lower than that in the control field without vetiver grass trap stripe.The control efficiency of 2-year vetiver grass trap stripe on SSB was higher than that of 1-year vetiver grass trap stripe.The rice seedling protection rates of 2-year vetiver grass trap stripe of5 m,3 m,and1 m cluster spacings to paddy field were 63.6%,47.5% and69.7%,respectively,and the control range was>20 m.While in the area with the density of 85.45 individuals per hundred hills where SSB occurred seriously,the field experiment results showed that the SSB population decline rate in the paddy field with cluster spacing of 4 m and line spacing of 50 m vetiver grass trap stripe was 84.2%.Our study clarified that the optimal planting pattern of the trap plant vetiver grass around the paddy ridge or roadside for controlling rice stem borer was cluster spacing of 3-5 m and line spacing of 50-60 m.